Sealable valve bag and method for making a sealable valve bag

ABSTRACT

The valve bag includes a bag body having a valve end portion, the valve end portion constructed to form a filling passage in which a valve sleeve is inserted. The valve sleeve has a first end extending into the interior of the valve bag and a second end secured to the bag body. A valve protection member is secured to the second end.

RELATED APPLICATION

[0001] This application is a continuation-in-part of U.S. patent application Ser. No. 09/847,672 filed on May 2, 2001.

TECHNICAL FIELD

[0002] The invention relates generally to sealable valve bags and more specifically to the valve sleeve used to fill and seal the valve bags. These shipping sacks are commonly used to contain and transport granular products, examples of which are fertilizers, animal feeds or grain.

BACKGROUND ART

[0003] Flexible bags such as paper shipping sacks may include a sealable valve sleeve placed in a filling valve, the filling valve is located in a corner of the flexible bag to allow introduction of material that is to be held within the bag. These shipping sacks are commonly used to contain and transport material such as granular products, examples of which are fertilizers, animal feeds or grain. The sealable sleeve provides a convenient means to fill and securely close the flexible bag to prevent the contents of the bag from leaking or sifting out of the bag once the bag has been filled. Sleeves may be constructed of a variety of materials such as paper, polyethylene tubing or a thermoplastic liner.

[0004] A typical sleeve for a paper shipping sack, such as a pasted valve type multiwall shipping sack, is made from a rectangular sheet of kraft paper that is rolled into a cylindrical shape and secured in the cylindrical shape by overlapping or abutting the opposing edges of the sheet of paper to one another and gluing to form a seam. Such a sleeve is described in commonly assigned U.S. Pat. No. 6,164,823, the disclosure of which is hereby expressly incorporated by reference. In order to seal the valve sleeve and therefore the valve passage after the shipping sack is full, heat, typically generated by ultrasonic vibrations, is applied to the exterior surface of the valve sleeve melting the thermoplastic film liner sealing the sleeve and securing the contents within the shipping sack.

[0005] However, due to the interaction between the vibrating jaw of the ultrasonic generator and the outer surface of the valve sleeve, the valve sleeve is often damaged. The damage to the valve sleeve may make it possible for the contents of the bag to leak or sift out of the bag even after the sealing operation has been completed.

[0006] Valve sleeves have been constructed of multiple sheets of paper to strengthen and protect the valve sleeve of the flexible bag. This design has a high non-conforming rate, often as great as fifteen percent, because the difficulties of aligning the several sheets of paper to the valve sleeve results in discontinuities around the valve sleeve and allow product to escape from the bag.

[0007] Further, valve sleeves which have been constructed of multiple sheets of paper for strength and protection often resist simple efforts made to open and prepare them for filling. As a result, a common vacuum opening system is generally not robust enough to deform the valve sleeve so the filling tube may be inserted. Additional steps are required to insure that the valve sleeve is open and capable of receiving the filling tube, such as applying force along the edges of the valve sleeve to cause it to vertically bow open or using a mechanical finger to provide resistance against the vacuum force.

BRIEF DESCRIPTION OF THE DRAWINGS

[0008]FIG. 1 is a perspective view of the valve bag, having a valve sleeve constructed in accordance with the invention, with the valve sleeve in the closed position;

[0009]FIG. 2 is a perspective view of the valve bag of FIG. 1, with the valve sleeve in the open position;

[0010]FIG. 3 is a cross-sectional view of the valve sleeve of FIG. 1, taken along line 1-1 of FIG. 1;

[0011]FIG. 4 is a cross-sectional view of the valve sleeve of FIG. 2, taken along the line 2-2 of FIG. 2 and showing the ultrasonic generator in contact with the protection member;

[0012]FIG. 5 is a view similar to FIG. 2, showing text or graphics on the protective member;

[0013]FIG. 6 is a view similar to FIG. 4, showing the protective member extending into the valve passage.

[0014]FIG. 7 is a cross-sectional view of an alternate embodiment of the valve bag and sleeve in the unfilled position;

[0015]FIG. 8 is a perspective view showing a valve bag and sleeve in an upside down position; and

[0016]FIG. 9 is a view similar to FIG. 7, showing the valve bag and sleeve in the filled position.

DETAILED DESCRIPTION OF THE EMBODIMENTS

[0017] A valve sleeve for a flexible bag constructed in accordance with the present invention includes a cylindrical tube including a heat sealable liner and protective member secured to the cylindrical tube. The protective member is arranged to cover a portion of one end of the valve sleeve extending from the valve passage protecting the valve during the sealing process.

[0018] A flexible bag having a valve sleeve constructed to include a valve sleeve in accordance with the invention will be resistant to the damage caused during sealing of the valve sleeve and prevent contents of the flexible bag from escaping due to the damage.

[0019] Further, a flexible bag having a valve sleeve constructed to include a protective member in accordance with the invention will be easier to manufacture and result in less scrap and non-conforming valve bags. The protective member of the present invention is external to the valve passage to prevent the possibility of discontinuities, and is smaller than the valve sleeve itself to facilitate alignment, both of these improvements make the flexible bag easier to manufacture and decrease the non-conforming rate.

[0020] Still further, a flexible bag having a valve sleeve secured to a side wall using an adhesive dot in accordance with the invention provides a simple way to prepare and open the valve sleeve for filling. The upper and lower surfaces of the valve sleeve may be deformed, using a known vacuum opening system, to allow a filling nozzle to be inserted into the valve sleeve passage. Deformation of the valve sleeve occurs because the adhesive dot affixed to the lower surface, or the protective member, resists the opening force provided by the vacuum system. As a result of these counteracting forces the upper surface is forced to deform and separate from the protective member, which is affixed the lower surface, to form the valve sleeve passage. As material is inserted into the interior, via the filling nozzle positioned within the valve sleeve passage, the flexible bag expands causing the protective member and the lower surface of the valve sleeve to pull away from the adhesive dot and the side wall.

[0021] Additional benefits and features of the invention will be apparent to those skilled in the art from a review of the following detailed description taken in conjunction with the drawings and applied claims.

[0022] The following description of the disclosed embodiment is not intended to limit the scope of the invention to the precise form or forms detailed herein. Instead, the following description is intended to be illustrative of the principles of the invention so that others may follow its teachings.

[0023] Referring now to the drawings, a valve bag capable of being sealed is shown in FIGS. 1-4. A valve bag 10 includes side walls 12, 14, in-folded flap 16, and outer flaps 18, 20. The valve bag 10 is preferably a valve bag having multiple walls A, B, C adhered together, at least in portion, by layers of adhesive D.

[0024] The valve bag 10, in order to facilitate filling and subsequent sealing also includes a valve sleeve 22. The valve sleeve 22 is cylindrical tube that has a uniform length from its outside end 26, to its inside end 28. The valve sleeve 22 may be formed from a single, rectangular sheet of relatively stiff kraft paper having a thermoplastic film 24 that coats the entire interior of the valve sleeve 22, and such as disclosed and described in the aforementioned U.S. Pat. No. 6,164,823. A valve sleeve protection member 34 is affixed to the exterior of the valve sleeve 22, substantially adjacent to the outside end 26, and extending towards its inside end 28, substantially adjacent with side wall 12. The entire valve sleeve assembly 36, valve sleeve 22 and protection member 34 is affixed in the filling passage 38 created between the in-folded flap 16 and outer flaps 18, 20 and secured by adhesive D.

[0025] The filling of the valve bag 10, is accomplished by inserting a fill nozzle (not shown) into the valve sleeve passage 30 defined by the valve sleeve 22 and discharging material into the interior 32 of valve bag 10. Upon completion of filling, the valve sleeve 22 is typically sealed by positioning the outside end 26 between a head 40 and an anvil 42 of an ultrasonic generator. The protection member 34 is thus positioned between the head 40 and the valve sleeve 22. Ultrasonic energy generated by the vibration of the head 40 activates the thermoplastic film 24 to seal the valve sleeve 22. The protection member 34 protects the kraft paper surface of the valve sleeve 22 from damage created by the motion of the head 40. Accordingly, a tight seal is achieved and damage, such as holes or imperfections, that would allow filling material to escape the valve bag 10 after sealing was complete is reduced.

[0026] In another embodiment shown in FIG. 5, the valve bag 10 includes a valve sleeve protection member 34 attached to a surface 44 of the valve sleeve 22. The valve sleeve protection member 34 has been adapted to display text or graphics 46.

[0027] In another embodiment shown in FIG. 6, the protective member 34 is shown to extend into the valve bag filling passage 38. The protective member 34 is attached to the lower surface 48 with adhesive D. The protective member 34 extends inward towards the interior 32 of the valve bag 10 but is not attached to any of the multiple walls A, B, or C.

[0028] In another embodiment shown in FIG. 7, the valve bag 10 is shown lying substantially horizontal in the collapsed or unfilled position. The valve sleeve 22 and valve sleeve protection member 34, in the unfilled position, are adjacent to the multiple walls A, B, and C. Further the protective member 34 may be affixed to the side wall 12 by an adhesive dot 48 as shown in detail in FIG. 8. The dotted line 50, in FIG. 8, represents the position of the adhesive dot 48 when the valve bag 10 is in the unfilled position. The adhesive dot 48 may be a starch or resin based compound. An opening device (not shown), such as a suction cup or mechanical finger, may be applied to the outside end 26 of the valve sleeve 22 to facilitate opening the valve sleeve 22. For example, the valve sleeve may be opened by using the suction cup to apply a vacuum force to the top surface 52, while the protective member 34 is held firmly against the side wall 12 by the adhesive dot 48. A filling nozzle (not shown) may then be inserted in to the valve sleeve passage 30 and material may be discharged into the interior 32.

[0029] The valve bag 10 in FIG. 9 is shown in a substantially full position. The adhesive dot 48 is shown attached to the side wall 12 after the valve bag 10 has been filled and expanded. The discharge of the material through the valve sleeve passage 30 into the interior 32 causes the valve bag 10 to fill and expand. The filling action of the valve bag, in turn, causes the valve sleeve 22 to separate from the side wall 12. The adhesive dot 48 may remain affixed to the side wall 12 to provide a clean surface on the protective member 34 to which later sealing operations may be performed. It may be necessary, depending on the material chosen for the adhesive dot, to provide an additional coating to the surface of the protective member 34 to insure complete separation of the adhesive from the protective member.

[0030] While the valve sleeve 22 has been described as being secured to the side of the valve bag 10 by an adhesive dot 48, it will be appreciated that more than one adhesive dot may be utilized to secure the valve sleeve 22. Moreover, a pattern of dots may be used. Alternatively, a strip or strips of adhesive may be used, or areas of adhesive may be used.

[0031] Additionally, while resin or starch based adhesives are contemplated, other suitable adhesives may be used.

[0032] Those skilled in the art will appreciate that, although the teachings of the invention have been illustrated in connection with a certain embodiment, there is no intent to limit the invention to said embodiment. On the contrary, the intention of this application is to cover all modifications and embodiments fairly falling within the scope of the appended claims either literally or under the doctrine of equivalents. 

What is claimed is:
 1. A valve bag apparatus for the containment of material, comprising: a bag body portion having a valve end portion; a filling passage formed in the bag body at the valve end portion; a sealable valve sleeve secured within the filling passage, the sealable valve sleeve having a first end extending into the interior of the bag body and a second end extending exteriorly from the bag body; a protection member secured to the second end; and an adhesive member securing the valve sleeve to the bag body.
 2. The valve bag of claim 1, wherein the adhesive member is secured to the valve sleeve.
 3. The valve bag of claim 1, wherein the adhesive member is secured to the protection member.
 4. The valve bag of claim 1, wherein the adhesive member is a starch based glue.
 5. The valve bag of claim 1, wherein the adhesive member is a resin based glue.
 6. A method of constructing a valve bag, the method comprising the steps of: providing a bag body portion having a valve end portion; constructing a filling passage in the bag body at the valve end portion; securing a valve sleeve within the filling passage, the valve sleeve having a first end extending into the bag body and a second end extending exteriorly from the bag body; securing a protective member to the second end; and affixing the protective member to a side wall.
 7. The method of claim 6, wherein the protective member is affixed to the side wall using an adhesive.
 8. The method of claim 6, wherein the protective member is affixed to the side wall using a starch based glue.
 9. The method of claim 6, wherein the protective member is affixed to the side wall using a resin based glue.
 10. A method of filling a valve bag, the method comprising the steps of: providing an unerected valve bag having a valve end portion; inserting a valve sleeve having a protective member into the valve end portion; creating a valve sleeve passage in the valve end portion having a fixed lower surface and a moveable top surface; inserting a filling member in valve sleeve passage; discharging material through the filling member into the valve bag thereby reconfiguring the valve bag from the unerected position to an erect position.
 11. The method of claim 10, wherein the secured lower surface is secured to a side wall of the valve bag.
 12. The method of claim 10, wherein the secured lower surface is secured using an adhesive material.
 13. The method of claim 12, wherein the adhesive material is a starch based adhesive.
 14. The method of claim 12, wherein the adhesive material is a resin based adhesive.
 15. The method of claim 10, wherein the valve sleeve passage is created by moving the top surface using a suction device.
 16. The method of claim 10, wherein the valve sleeve passage is created by moving the top surface using a mechanical actuator. 